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Dual optimization strategy for N and P removal in a biological wastewater treatment plant / MinHan Kim in Industrial & engineering chemistry research, Vol. 48 N° 13 (Juillet 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 13 (Juillet 2009) . - pp. 6363–6371 Titre : Dual optimization strategy for N and P removal in a biological wastewater treatment plant Type de document : texte imprimé Auteurs : MinHan Kim, Auteur ; A. Seshagiri Rao, Auteur ; ChangKyoo Yoo, Auteur Année de publication : 2009 Article en page(s) : pp. 6363–6371 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Nitrogen  removal  Phosphorus  removal  Biological  nutrient  removal  process  Systematic  approach Résumé : A systematic approach is proposed to find optimal operational conditions for nitrogen and phosphorus (N, P) removal in a biological nutrient removal process. The approach is a dual optimization strategy using modeling, variable selection, design of experiments, and optimization with multiple response surface methodology. The study focused on determining interactive effects between independent variables for N and P removal, which were selected through a new sensitivity analysis considering the effluent quality index. After selecting key operational variables, a multiple response surface model based on a new desirability function was used for the dual optimization of both N and P removal. The proposed method was applied to a standard A2O process and obtained the optimized removal efficiencies of 78.0% and 80.0% for N and P, respectively. This study confirmed that the proposed dual optimization method was useful to systematically optimize N and P removal in a biological nutrient removal process and also can be applied to any other biological processes. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801689t [article] Dual optimization strategy for N and P removal in a biological wastewater treatment plant [texte imprimé] / MinHan Kim, Auteur ; A. Seshagiri Rao, Auteur ; ChangKyoo Yoo, Auteur . - 2009 . - pp. 6363–6371. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 13 (Juillet 2009) . - pp. 6363–6371 Mots-clés : Nitrogen  removal  Phosphorus  removal  Biological  nutrient  removal  process  Systematic  approach Résumé : A systematic approach is proposed to find optimal operational conditions for nitrogen and phosphorus (N, P) removal in a biological nutrient removal process. The approach is a dual optimization strategy using modeling, variable selection, design of experiments, and optimization with multiple response surface methodology. The study focused on determining interactive effects between independent variables for N and P removal, which were selected through a new sensitivity analysis considering the effluent quality index. After selecting key operational variables, a multiple response surface model based on a new desirability function was used for the dual optimization of both N and P removal. The proposed method was applied to a standard A2O process and obtained the optimized removal efficiencies of 78.0% and 80.0% for N and P, respectively. This study confirmed that the proposed dual optimization method was useful to systematically optimize N and P removal in a biological nutrient removal process and also can be applied to any other biological processes. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801689t

Enhanced control of unstable cascade processes with time delays using a modified smith predictor / S. Uma in Industrial & engineering chemistry research, Vol. 48 N° 6 (Mars 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 6 (Mars 2009) . - pp. 3098–3111 Titre : Enhanced control of unstable cascade processes with time delays using a modified smith predictor Type de document : texte imprimé Auteurs : S. Uma, Auteur ; M. Chidambaram, Auteur ; A. Seshagiri Rao, Auteur Année de publication : 2009 Article en page(s) : pp. 3098–3111 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Cascade  controller  Smith  predictor  structure  Unstable  cascade  Direct  synthesis  method  Internal  model  control Résumé : This paper presents a simple cascade controller in the enhanced modified Smith predictor structure for control of open loop unstable cascade processes with/without zero. The proposed structure consists of two control loops, a secondary inner loop and a primary outer loop. The method has totally three controllers of which the secondary loop has one controller and the primary loop has two controllers. The secondary loop controller is designed using the internal model control (IMC) technique. The primary loop set point tracking and disturbance rejection controllers are designed using the direct synthesis method. The primary set point tracking controller is designed as a proportional, integral, and derivative (PID) controller with lag filter and the primary disturbance rejection controller is designed as a PID with lead−lag filter. Simulation studies have been carried out on various cascade unstable processes with/without zero. The present method gives significant disturbance rejection both in the inner and outer loops. Also, the proposed method shows significant improvement when compared to the recently reported methods in the literature. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801590e [article] Enhanced control of unstable cascade processes with time delays using a modified smith predictor [texte imprimé] / S. Uma, Auteur ; M. Chidambaram, Auteur ; A. Seshagiri Rao, Auteur . - 2009 . - pp. 3098–3111. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 6 (Mars 2009) . - pp. 3098–3111 Mots-clés : Cascade  controller  Smith  predictor  structure  Unstable  cascade  Direct  synthesis  method  Internal  model  control Résumé : This paper presents a simple cascade controller in the enhanced modified Smith predictor structure for control of open loop unstable cascade processes with/without zero. The proposed structure consists of two control loops, a secondary inner loop and a primary outer loop. The method has totally three controllers of which the secondary loop has one controller and the primary loop has two controllers. The secondary loop controller is designed using the internal model control (IMC) technique. The primary loop set point tracking and disturbance rejection controllers are designed using the direct synthesis method. The primary set point tracking controller is designed as a proportional, integral, and derivative (PID) controller with lag filter and the primary disturbance rejection controller is designed as a PID with lead−lag filter. Simulation studies have been carried out on various cascade unstable processes with/without zero. The present method gives significant disturbance rejection both in the inner and outer loops. Also, the proposed method shows significant improvement when compared to the recently reported methods in the literature. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801590e